It could well be that they have a 'service provider' for bulk email that requires a list of email addresses and content to be handed over in advance. I can't im

It could well be that they have a 'service provider' for bulk email that requires a list of email addresses and content to be handed over in advance. I can't imagine what effects it would have on user privacy though. Or perhaps the text was written by someone who had no idea of how subscribe/unsubscribe worked and took a 'reasonable' guess.